1. Field of The Invention
The present invention relates to a tray transferring apparatus of a sorter equipped with slot liners and transfer wheels adapted for transferring bin trays each having a pair of pin trays, and more particularly to a tray transferring apparatus of a sorter which supports and transfers the whole bin tray by a rack moving in the vertical direction by using the driving power of the transfer wheel.
2. Description of The Prior Art
Generally, a known sorter of copy machine, which is equipped with slot liners and transfer wheels, has adopted a method of arranging and separating the copy sheets by transferring successively a plurality of bin trays.
An example of the conventional tray transferring apparatus, as disclosed in U.S. Pat. Nos. 4,328,963 and 4,332,377, was provided with a wire of which one side was connected to the pin of the bin tray located at the lowest part of the sorter and the other side is connected to the spring positioned at the upper portion of the sorter. In the practical products of the sorter having the transferring apparatus disclosed in the above U.S. patents, The bin tray transferring apparatus adopted a spring instead of the wire was directly connected to the pin of the bin tray located at the lowest part of the sorter. However, such type of sorters should use the spring which had relatively large restoring power so that, when a pin was transferred downward, an instantaneous overload loaded at the transfer wheel might cause a loud noise.
There has been also proposed a known sorter using a drum cam instead of the transfer wheel. For examples, a sorter disclosed in U.S. Pat. No. 4,466,609 used two drum cams and a support frame, and a sorter disclosed in United Kingdom Patent No. 2,168,037 was equipped with auxiliary bin tray supporter separately provided and having the same shape as that of the slot liner so that the bin tray could move vertically upward and downward upon providing a simultaneous moving of the inner portion of the bin tray, pin side, and the outer portion of that, tap side. But, it has been noted that such type of bin tray transferring apparatus using the support frame had difficulty in applying to the sorter using the transfer wheel.
Also, as disclosed in Japanese Patent laid-open publication No. sho 60-232370, a transferring apparatus capable of using support frame in the construction of using the transfer wheel has been proposed. However, such type of transferring apparatus should have an auxiliary protrusion provided at a part of the outside of the radius of gyration of the transfer wheel and more equipments such as cams and outer springs adapted to drive the transfer wheel. Furthermore, this type of transferring apparatus should have a contact surface provided at the bin tray and adapted for contacting with the pin during driving the transferring apparatus, and the transfer wheel should move in revolution and precipitation at the same time.
Korean Patent Laid-Open Publication No. 91-371 disclosed a transferring apparatus of sorter adopting a method capable of reducing the noises by changing the shape of transfer wheel to have a camming mechanism. Also, as disclosed in Korean Patent Application Nos. 90-855 and 90-16620, which were applied by this applicant, there has been proposed another type of sorter having a slot liner having an inclined middle portion extending from the upper and lower vertical portions of the slot liner toward the ejecting section of the copy machine. This type of sorter could provide an advantage that the bin tray could advance closer to the ejecting section of the copy machine, thereby making it possible to receive and arrange the copies without any auxiliary guiding unit. However, it has been noted that there were a disadvantage that the sorter of this type was provided with a conventional transfer wheel, that is to say, the circular transfer wheel having first and second slots arranged along the diameter of said transfer wheel and extending radially inward from the circumference of said transfer wheel, thereby spending a long time for separating and arranging the copies so that it could separate and arrange the copies only two times during one rotation of the transfer wheel. Also, there was another disadvantage that the sorter adopted the method of urging usually the bin trays upwards by upwardly biasing the base pin of the bin tray by means of the spring mounted at the upper portion of the side plate of the sorter so that the upward and downward movements of the pin of the bin tray could not be smoothly carried out during the rotation of the transfer wheel, and a loud noise might be generated.
In an effort for solving the above-mentioned disadvantages, the applicant of this invention has proposed a sorter having a transfer wheel provided with three slots, as disclosed in Korean Patent Application No. 90-18264, instead of the above-mentioned transfer wheel provided with two slots. The sorter of this type could carry out one transferring operation for the bin tray during one third cycle of rotation of the transfer wheel as a result of the three slots each arranged at every 120.degree. on the transfer wheel and extending radially inward from a circumference of said transfer wheel, and also transfer slowly and upwardly another lower waiting bin tray according to the driving rate of the transfer wheel because the transfer wheel was also provided with involute portions each formed at sections which might contact with the pin of the bin so that a waiting pin tray could be smoothly and naturally located within the radius of gyration of said transfer wheel. Thus, this type of transfer wheel could be applied to various types of sorters provided with biasing units for urging the bin tray upwardly, said biasing units using a spring, a wire, a rack or a supporting mechanism.
However, the above-mentioned type of sorter had the transfer wheel comprising an integrally formed rotator and the three slots formed on the rotator. Therefore, there has been a disadvantage of enlarging the noise because of adding a noise generated while a bin tray seated on the upper portion of the transfer wheel was instantaneously received in a slot of said transfer wheel to the noise generated by the instantaneous overload during driving said transfer wheel in order to pick up downwardly and push upwardly the pin of the bin tray.